Do you know the correct name of this flower or fruit?

People here call it "Yesterday, Today and Tomorrow", but that name belongs to another flower, according to the Internet.  Like YT&T, it also changes to different colors; the middle plum-like portion changes to different colors - from yellow to green to black.  It has been black for over 1 week already.  This is the first time we've seen such flower.  We will be glad for any correction...